Fuel conversion reactor

Abstract

A fuel conversion reactor includes a shell-and-tube heat exchanger for controlling the temperature of a hot gaseous mixture produced by catalytic or non-catalytic reaction of a fuel with a gaseous fluid, and for controlling the temperature of the gaseous fluid and/or the fuel prior to the reaction. The reactor is either a catalytic or non-catalytic burner, or a fuel reformer for converting a fuel to hydrogen. A preferred reactor includes an outer shell having first and second ends and an inner surface, a primary inner shell extending into the outer shell, the primary inner shell defining a heat exchanging chamber and having primary and secondary ends, and a secondary inner shell having a first end located adjacent the secondary end of the primary inner shell. One or more outlet apertures are formed between the two inner shells for passage of the gaseous fluid out of the heat exchanging chamber. There are also a plurality of heat exchange tubes extending through the heat exchanging chamber between first and second tube sheets and connected to same. The first tube sheet is mounted in the primary inner shell while the second tube sheet is connected to the secondary inner shell. The tubes form passages for flow of the hot gaseous mixture in heat exchange contact with the gaseous fluid through the heat exchanging chamber, thereby preheating the gaseous fluid prior to reaction with the fuel. The adjacent ends of the inner shells form a disconnected joint and the secondary inner shell is free to move relative to the primary inner shell upon thermal expansion of the tubes.

1. A fuel conversion reactor comprising a shell-and-tube heat exchanger for heating a gaseous fluid prior to reaction with a fuel and for cooling a gaseous mixture produced by the reaction, said heat exchanger comprising:
 a primary shell member having primary and secondary ends and a sidewall extending between said ends and defining a heat exchanging chamber located within the shell member; 
 an inlet for introducing said gaseous fluid into said heat exchanging chamber; 
 a first tube sheet fixedly mounted on said primary shell member in the vicinity of said primary end and sealingly closing said heat exchanging chamber at one end of the chamber; 
 a second tube sheet device which is separate from said primary shell member and is located in the vicinity of said secondary end, said second tube sheet device forming another end of said chamber that is opposite said one end of the chamber; and 
 a plurality of heat exchange tubes extending from said first tube sheet to said second tube sheet device and rigidly connected to both the first tube sheet and the second tube sheet device, said heat exchange tubes providing passageways for said gaseous mixture to flow inside the tubes through said heat exchanging chamber; 
 wherein one or more outlet apertures are formed in the region of said secondary end of said primary shell member in order to provide at least one outlet for said gaseous fluid which flows through said heat exchanging chamber on a shell-side thereof during operation of said fuel conversion reactor; 
 wherein said second tube sheet device includes a secondary shell member having a peripheral sidewall, a first end located adjacent to said secondary end of the primary shell member and a second end spaced from the first end; 
 wherein the secondary shell member and the secondary end of the primary shell member together form a disconnected joint; and 
 wherein said second tube sheet device is free to move relative to said primary shell member upon thermal expansion of said heat exchange tubes. 
 
     
     
       2. A fuel conversion reactor according to  claim 1 , wherein said one or more outlet apertures are formed in at least one of said primary shell member and said second tube sheet device. 
     
     
       3. A fuel conversion reactor according to  claim 1 , wherein said one or more outlet apertures are formed between said primary shell member and said second tube sheet device. 
     
     
       4. A fuel conversion reactor according to  claim 1  including an outer shell having first and second ends and an outer shell wall extending between said first and second ends, said outer shell being closed at said second end, extending around said primary shell member and said second tube sheet device, and having an inlet for said fuel, wherein a fuel passageway is formed between said outer shell wall and said sidewall of the primary shell member and extends from said inlet for the fuel to said one or more outlet apertures. 
     
     
       5. A fuel conversion reactor according to  claim 1  wherein a gap is formed at said disconnected joint. 
     
     
       6. A fuel conversion reactor according to  claim 5 , wherein said one or more outlet apertures comprises said gap. 
     
     
       7. A fuel conversion reactor comprising a shell-and-tube heat exchanger for heating a gaseous fluid prior to reaction with a fuel and for cooling a gaseous mixture produced by the reaction, said heat exchanger comprising:
 a primary shell member having primary and secondary ends and a sidewall extending between said ends and defining a heat exchanging chamber located within the shell member; 
 an inlet for introducing said gaseous fluid into said heat exchanging chamber; 
 a first tube sheet fixedly mounted on said primary shell member in the vicinity of said primary end and sealingly closing said heat exchanging chamber at one end of the chamber; 
 a second tube sheet device which is separate from said primary shell member and is located in the vicinity of said secondary end, said second tube sheet device forming another end of said chamber that is opposite said one end of the chamber; and 
 a plurality of heat exchange tubes extending from said first tube sheet to said second tube sheet device and rigidly connected to both the first tube sheet and the second tube sheet device, said heat exchange tubes providing passageways for said gaseous mixture to flow inside the tubes through said heat exchanging chamber; 
 wherein one or more outlet apertures are formed in the region of said secondary end of said primary shell member in order to provide at least one outlet for said gaseous fluid which flows through said heat exchanging chamber on a shell-side thereof during operation of said fuel conversion reactor; 
 further comprising a first catalyst to catalyze the reaction of the fuel and the gaseous fluid, said catalyst being mounted in a secondary shell member having a peripheral sidewall, with an end of said peripheral sidewall being located adjacent said secondary end of the primary shell member and, together with said secondary end, forming a disconnected joint, said catalyst being arranged for flow of a mixture of said fuel and said gaseous fluid therethrough to produce said gaseous mixture. 
 
     
     
       8. A fuel conversion reactor according to  claim 7 , wherein the first catalyst comprises an autothermal reformation catalyst. 
     
     
       9. A fuel conversion reactor according to  claim 7 , wherein the first catalyst comprises a partial oxidation catalyst. 
     
     
       10. A fuel conversion reactor according to  claim 7 , wherein the first catalyst comprises a steam reformation catalyst. 
     
     
       11. A fuel conversion reactor according to  claim 7 , wherein the first catalyst comprises a combustion catalyst. 
     
     
       12. A fuel conversion reactor according to  claim 7 , further comprising a second catalyst arranged in said primary shell member in the vicinity of said primary end and outside said heat exchanging chamber. 
     
     
       13. A fuel conversion reactor according to  claim 12 , wherein the second catalyst is a water/gas shift reaction catalyst. 
     
     
       14. A fuel conversion reactor according to  claim 12 , wherein the second catalyst is a preferential oxidation catalyst. 
     
     
       15. A fuel conversion reactor according to  claim 1 , wherein said one or more outlet apertures are formed at said secondary end of said primary shell member. 
     
     
       16. A fuel conversion reactor according to  claim 1 , wherein said second tube sheet device includes a secondary shell member having a peripheral sidewall with a first predetermined diameter and a coaxial sleeve extension extending from said peripheral sidewall at an end thereof closest to said secondary end and having a second predetermined diameter different than said first predetermined diameter, wherein said sleeve extension has a free end located in the region of said one or more outlet apertures which are formed at or near said secondary end of said primary shell member, and wherein said secondary shell member is relatively movable during use of said fuel conversion reactor between a first position wherein said one or more apertures are partially blocked by said sleeve extension and a second position where said one or more apertures are at least substantially open for passage of said gaseous fluid. 
     
     
       17. A fuel conversion reactor according to  claim 1 , wherein said second tube sheet device includes a secondary shell member having a peripheral sidewall with a first internal diameter, said primary shell member has a primary external diameter and a coaxial sleeve extension extending from its sidewall at its secondary end, said sleeve extension having an external diameter different from said primary external diameter and different from said first internal diameter and having a free end located in the region of said one or more outlet apertures which are formed around said second tube sheet device, and wherein said secondary shell member is relatively movable during use of said fuel conversion reactor between a first position wherein said one or more apertures are partially blocked by said sleeve extension and a second position where said one or more apertures are at least substantially open for passage of said gaseous fluid. 
     
     
       18. A fuel conversion reactor according to  claim 4 , said secondary shell member further comprising a secondary inner shell member and, said shell-and-tube heat exchanger further comprising: a further passageway formed between said secondary inner shell member and said outer shell and extending from said first end to said second end of the secondary inner shell member, for flow of a mixture of said fuel and said gaseous fluid therethrough. 
     
     
       19. A heat exchanging apparatus according to  claim 1 , wherein baffle plates are mounted within said primary shell member between said first tube sheet and said second tube sheet device. 
     
     
       20. A fuel conversion reactor comprising a shell-and-tube heat exchanger for heating a gaseous fluid prior to reaction with a fuel and for cooling a gaseous mixture produced by the reaction, said heat exchanger comprising:
 a primary shell member having primary and secondary ends and a sidewall extending between said ends and defining a heat exchanging chamber located within the shell member; 
 an inlet for introducing said gaseous fluid into said heat exchanging chamber; 
 a first tube sheet fixedly mounted on said primary shell member in the vicinity of said primary end and sealingly closing said heat exchanging chamber at one end of the chamber; 
 a second tube sheet device which is separate from said primary shell member and is located in the vicinity of said secondary end, said second tube sheet device forming another end of said chamber that is opposite said one end of the chamber; 
 one or more outlet apertures are formed in the region of said secondary end of said primary shell member in order to provide at least one outlet for said gaseous fluid which flows through said heat exchanging chamber on a shell-side thereof during operation of said fuel conversion reactor; 
 a plurality of heat exchange tubes extending from said first tube sheet to said second tube sheet device and rigidly connected to both the first tube sheet and the second tube sheet device, said heat exchange tubes providing passageways for said gaseous mixture to flow inside the tubes through said heat exchanging chamber; and 
 an outer shell having first and second ends and an outer shell wall extending between said first and second ends, said outer shell being closed at said second end, extending around said primary shell member and said second tube sheet device, and having an inlet for said fuel, wherein a fuel passageway is formed between said outer shell wall and said sidewall of the primary shell member and extends from said inlet for the fuel to said one or more outlet apertures. 
 
     
     
       21. A fuel conversion reactor comprising a shell-and-tube heat exchanger for heating a gaseous fluid prior to reaction with a fuel and for cooling a gaseous mixture produced by the reaction, said heat exchanger comprising:
 a primary shell member having primary and secondary ends and a sidewall extending between said ends and defining a heat exchanging chamber located within the shell member; 
 an inlet for introducing said gaseous fluid into said heat exchanging chamber; 
 a first tube sheet fixedly mounted on said primary shell member in the vicinity of said primary end and sealingly closing said heat exchanging chamber at one end of the chamber; 
 a second tube sheet device which is separate from said primary shell member and is located in the vicinity of said secondary end, said second tube sheet device forming another end of said chamber that is opposite said one end of the chamber; 
 one or more outlet apertures are formed in the region of said secondary end of said primary shell member in order to provide at least one outlet for said gaseous fluid which flows through said heat exchanging chamber on a shell-side thereof during operation of said fuel conversion reactor; and 
 a plurality of heat exchange tubes extending from said first tube sheet to said second tube sheet device and rigidly connected to both the first tube sheet and the second tube sheet device, said heat exchange tubes providing passageways for said gaseous mixture to flow inside the tubes through said heat exchanging chamber; 
 wherein said second tube sheet device includes a secondary shell member having a peripheral sidewall with a first predetermined diameter and a coaxial sleeve extension extending from said peripheral sidewall at an end thereof closest to said secondary end and having a second predetermined diameter different than said first predetermined diameter, wherein said sleeve extension has a free end located in the region of said one or more outlet apertures which are formed at or near said secondary end of said primary shell member, and wherein said secondary shell member is relatively movable during use of said fuel conversion reactor between a first position wherein said one or more apertures are partially blocked by said sleeve extension and a second position where said one or more apertures are at least substantially open for passage of said gaseous fluid.